This description generally relates to surgical robotics, and particularly to an instrument device manipulator capable of rotating a surgical tool.
Robotic technologies have a range of applications. In particular, robotic arms help complete tasks that a human would normally perform. For example, factories use robotic arms to manufacture automobiles and consumer electronics products. Additionally, scientific facilities use robotic arms to automate laboratory procedures such as transporting microplates. In the medical field, physicians have started using robotic arms to help perform surgical procedures.
In a surgical robotic system, a robotic arm is connected to an instrument device manipulator, e.g., at the end of the robotic arm, and is capable of moving the instrument device manipulator into any position within a defined work space. The instrument device manipulator can be detachably coupled to a surgical tool, such as a steerable catheter for endoscopic applications or any of a variety of laparoscopic tools. The instrument device manipulator imparts motion from the robotic arm to control the position of the surgical tool, and it may also activate controls on the tool, such as pull wires to steer a catheter. Additionally, the instrument device manipulator may be electrically and/or optically coupled to the tool to provide power, light, or control signals, and may receive data from the tool such as a video stream from a camera on the tool.
To robotically drive an endoscope or other elongate surgical tool, it is often desirable to both articulate in a desired linear direction and “roll” in a desired angular direction. As used herein, the term “roll” means to rotate the endoluminal or other elongate surgical tool about a longitudinal axis of the surgical tool. In current elongated medical devices, roll in the device shafts is often achieved at the expense of pull-cable management. For example, in some laparoscopic devices on the market, roll of the device shaft may be accomplished by simply twisting the actuation pull wires (used for manipulation of the device's end effectors and/or wrist) around each other at the same rate as the shaft. Due to mechanically-limited revolutions in either direction, the twist in the cables show little to no adverse effect on either roll or grasper manipulation. Nevertheless, this lack of pull-wire management results in noticeably varying levels of friction throughout the shaft rotations. The accumulated friction steadily increases with each rotation until the pull wires are tightly bound around one another, much like a wire-rope, until the pull wires may no longer be able to overcome the resulting friction to exert tension on the device's end effectors and/or wrist.
In some products, articulation and roll are de-coupled using a robotic outer “sheath” to enable pitch and yaw articulation, while a flexible laparoscopic tool controls insertion roll and end-effector actuation. However, this results in an unnecessarily large system with two separate modules controlling different degrees of freedom. Separate modules complicate the pre-operative workflow because the operator must now register two sets of devices relative to the patient. In manual endoscopes, knobs and dials actuate the distal tip of the scope while rotation of the shaft is achieved by twisting the entire proximal end of the tool. As a result, when rolling the scope, the operator is forced to contort into an uncomfortable, compensatory position in order to operate the knobs and dials. These contortions are undesirable; thus, necessitating a different approach.
Accordingly, there is a need for surgical tool manipulators that are capable of “rolling” endoluminal and other elongate surgical tools without compromise to the tools actuation and articulation capabilities. There is a further need to provide surgical drapes which are compatible with such manipulators.